Toy automobile driving mechanism



Aug. 31, 1954 MCRQSKEY 2,687,595

TOY AUTOMOBILE DRIVING MECHANISM Filed July 13. 1953 [e onard h. M P0574 IN V EN TOR.

Patented Aug. 31, 1954 Ul'lED STATE A'lNT OFFICE- TOY AUTOMOBILE DRIVING MECHANISM Leonard H. McRoskey, Beverly Hills, Calif., as-

signor to Wen-Mac Corporation, Beverly Hills, Galifl, a corporation of California Application July 13, 1953, Serial No. 367,404

3 Claims. 1

The present invention relates generally to motor driven toys, and more particularly to a mechanism for transmitting power to a driven member thereof.

Miniature motors of high-speed are employed for motivating toys of various types. Such highspeed motors, as for example, a miniature onecylinder internal combustion engine having a speed of from approximately 15,000 to 25,000 R. P. M., are of very low power and, consequently, in direct drive arrangements may be killed or stalled readily upon the sudden application of opposing force against the action of the motor. A force suflicient to kill a miniature high-speed motor is met with in starting and accelerating a Cir toy wheeled vehicle, the power of such motor I .being too weak to overcome the inertia of the vehicle. Though special gear mechanisms may be employed for drivingly connecting the motor to the wheels, such devices are usually too complicated for application in toys, are expensive to manufacture, and often substantially reduce the speed of the vehicle.

It is an object of this invention to provide a simple, yet efiicient mechanism for imparting driving power to a driven member from a motor of low power, and which is especially suited for use in a toy.

It is another object of this invention to provide a motor-driven toy, wherein the driven member is rotated by a mechanism which allows the motor to run smoothly even though force be applied against rotation of the driven member.

Another object of this invention is to provide a toy wheeled vehicle wherein a propulsion wheel thereof is drivingly connected to a miniature motor in such a way that the full force of inertia opposing motion of the vehicle is not applied against the motor during starting operations.

Further objects and advantages of the invention will become apparent from the following part of the specification, in which the details of construction and the mode of operation of a preferred embodiment of the invention are described with reference to the attached drawing which is for illustrative purposes only, and wherein:

Fig. 1 is a perspective view of a toy racing car embodying the invention; and

Fig. 2 is a vertical section of a propulsion wheel which constitutes the left front wheel of the racing car shown in Fig. 1, and shows such wheel associated with the motor of the car.

Referring to the drawing, reference numeral I0 designates the body or frame of a toy vehicle, two free wheels of which are shown at II and I 2, and a propulsion wheel at I3. The propulsion wheel I3 is drivingly connected to the miniature one-cylinder internal combustion engine I4 mounted in the front end of the vehicle.

Referring to Fig. 2 of the drawing, reference numeral I5 designates the drive shaft of the engine M. It has a shaft extension I6 of reduced diameter, and an annular ridge or ruff I! at the base of the extension I6 for holding the shaft against axial movement thereof in the engine. The shaft extension I6 is threaded as indicated at IS, to receive an internally threaded shaft adapter I 9. A flywheel 20 having an inwardly extending hub portion 2i is centered on and rotatable with the shaft extension, rotation of the flywheel with respect to the shaft being prevented by the pressure of the adapter I9 forcing the hub portion 2i of the flywheel in tight frictional engagement with the outer face of the ruff I'I. One

* face of the flywheel 20 is concave at its central portion and has a convex annulus 22 concentric with the axis of the flywheel. The shaft extension !6 and the adapter I9 constitute the axle for the propulsion wheel.

The propulsion wheel I3 is arranged on the adapter I9 adjacent to the flywheel 20. The hub portion of the propulsion wheel constitutes a bearing or bushing 23 centering the wheel I3 on the axle but being rotatable independently of the axle. Except for the bushing 23 the propulsion wheel is formed of a flexible material such as, for example, rubber, or an elastic plastics material. A suitable plastics material for this purpose is vinyl chloride having a softening agent mixed with it, for giving the material a consistency and flexibility similar to that of the rubber in automobile tires. The propulsion wheel is concave-convex and has an enlarged peripheral portion or tire 24. The wheel I3 is arranged on the axle with its convex side adjacent to the concave face of the flywheel 20, and it is held I on the axle against axial movement thereof with respect to the axle by-means of the washer 2B which is held on the end of adapter I9 by means of the nut 21. The washer 26 is formed of a resilient material which is dished to provide a periphery thereof conforming to the shape of that part of the propulsion wheel with which it contacts. The washer 26 holds the propulsion wheel against the flywheel 20 with slight pressure but permits easy slipping between the contacting surfaces of the flywheel and the propulsion wheel.

It is clear from the above that upon rotation of the propulsion wheel, and because of its concave-convex configuration, along with the thereby deriving more and more power from the flywheel until in time the speed of the propulsion wheel approaches that of the flywheel. Since the tire portion of the wheel I3 is bulged toward the flywheel as shown in the drawing, any pressure exerted radially of the propulsion wheel from a point on its periphery, will tend to urge the propulsion wheel into tighter frictional engagement with the flywheel. Thus, a wheeled vehicle provided with the power transmitting de vice of this invention will be caused to move forward by the frictional engagement of the propulsion wheel and the driving member of the power transmitting device when the vehicle is placed on a supporting surface.

In the embodiment shown in the drawing, the flywheel is provided with an annular groove in the periphery or rim thereof for accomniodating a cord or starting string 3|, by which torque is applied to the motor for starting. When the motor has been started it will rotate the flywheel 20 though the propulsion wheel l3 may remain still. When the toy is placed down on a surface, its weight will increase the frictional engagement between the propulsion wheel [3 and the flywheel in such a way as to initially impart driving power to the propulsion wheel. The slipping that occurs between the flywheel and the propulsion wheel allows the miniature motor to run without having to overcome the full force of inertia of the toy. The toy will gradually build up in speed, and as it does so, more and more drive will be imparted to the propulsion wheel, thereby accelerating the toy to the highest speed capable of the vehicle.

I claim:

1. A toy vehicle comprising a body, ground engaging wheels on said body, at least one of said wheels being a propulsion wheel, at least all but the hub portion of said propulsion wheel being formed of elastic material, an axle for said propulsion wheel, a flywheel centered on and rotatable with said axle, a motor mounted on the front portion of said body, said axle being drivingly connected to said motor, said propulsion wheel being supported and centered on said axle but rotatable independently thereof, one face of said flywheel bing concave and providing a convex annulus concentric with said axle, said propulsion wheel being concavo-convex with its convex side adjacent said one face of the flywheel, the tire portion of said propulsion wheel being enlarged, the diameter of said flywheel being less than that of said propulsion wheel, and a washer on the concave side of said propulsion wheel urging it toward said flywheel.

2. A self-powered toy comprising a body, a motor carried by said body, an axle driven by said motor, a circular driving member mounted on and rotatable with said axle, one face of said driving member being concave and providing a convex annulus concentric with said axle, a concavo-convex driven member centered on but rotatable independently of said axle, at least all but the hub portion of said driven member being formed of elastic material, said driven member being arranged on said axle with its convex side adjacent said one face of said drive member, and means arranged on the concave side of said driven member for holding said driven member slidingly against said driving member, whereby when said driven member is rotated the centrifugal force thereof will urge it into frictional engagement with said driving member.

3. A self-powered toy comprising a body, a motor carried by said body, a shaft driven by said motor, a driving member mounted on and rotatable with said shaft, one face of said driving member being concave, a concave-convex driven member centered on but rotatable independently of said shaft, at least all but the hub portion of said driven member being formed of elastic material, said driven member being arranged on said shaft with its convex side adjacent said one face of said driving member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,260,770 Brownlee Oct. 28, 1941 2,340,415 Eason Feb. 1, 1944 2,495,090 Borden Jan. 17, 1950 2,664,982 Orzabal Jan. 5, 1954 FOREIGN PATENTS Number Country Date 348,823 Italy June 1, 1937 OTHER REFERENCES Popular Mechanics, vol. 94, No. 1 (pages -153), July 1950. 

